1. Technical Field
This invention relates generally to band saws and more particularly to a flanged guide roller with air flow passages there though to help dissipate heat from the roller during use thereof.
2. Background of the Invention
Conventionally band saws have a pair of blade guides which are located one on each of respective opposite sides of the active cutting portion of the saw blade. One known conventional band saw guide comprises a pair of slide blocks spaced apart from one another and mounted on a backing plate. The saw band passes through the gap between the slide blocks that are closely adjacent but spaced from opposite faces of the blade and the backing plate engages the edge of the blade to counteract forces imposed on the blade during cutting. The slide blocks are located rearwardly from the teeth because of their set to cut a kerf that is wider than the blade thickness. There may also be rollers that rollingly engage opposite faces the blade and by way of example of the same reference maybe had to U.S. Pat. No. 4,290,330 granted Sep. 22, 1981 to I. Washio et al and entitled “Bandsaw Blade Guiding Apparatus”.
Another known guide comprises a pair of rollers that rollingly engage respective opposite faces of the band blade and a third roller that rollingly engages the back edge of the blade. The rollers do not generate as much heat as do the slide blocks from frictional engagement with the blade.
A still further blade guide comprises a roller that has an outwardly projecting flange on one edge thereof. The rear edge of the blade engages the flange and a face of the blade engages the outer face of the roller. The one roller guide is much simpler than some of the other arrangements but the useful life of roller is shortened by heat generated by frictional contact of the blade with the roller and particularly the sliding contact between the rear edge of the blade and the flange on the guide roller. By way of example of a flanged roller blade guide reference may be had to U.S. Pat. No. 2,688,990 granted Sep. 14, 1954 to W. Bushey et al and entitled “Band Saw Guide” The disclosed guide employs a back-up roller for each of the respective pair of guide rollers.